Disparities in mobile phone use among adults with type 2 diabetes participating in clinical trials 2017-2021

Lay Summary Mobile health (mHealth) programs provide a convenient and effective approach to supporting health for people with chronic conditions like diabetes. We examined individual characteristics associated with smartphone ownership and health app use in 2 separate samples of adults with type 2 diabetes, collected a few years apart (2017-2018 and 2020-2021). In the earlier sample (N = 422), 87% owned a smartphone and among those, 49% had used a health app. People with low income and people with limited health literacy had 61% and 50% lower odds of owning a smartphone, respectively. Comparatively, in the later sample (N = 330), almost all participants (98%) owned a smartphone and 70% of those had used a health app. However, older people (>= 60 years old), people with a high school degree or less education, and people with limited health literacy had 78%, 58%, and 66% lower odds (respectively) of having used a health app. Our findings support thoughtful consideration of how and to whom apps are presented in both research and clinical contexts to avoid worsening health disparities. Smartphone access is not the only prerequisite for use of mHealth tools. Despite smartphone ownership becoming ubiquitous, it is unclear whether and where disparities persist in experience using health apps. In 2 diverse samples of adults with type 2 diabetes collected 2017-2018 and 2020-2021, we examined adjusted disparities in smartphone ownership and health app use by age, gender, race, education, annual household income, health insurance status, health literacy, and hemoglobin A1c. In the earlier sample (N = 422), 87% owned a smartphone and 49% of those had ever used a health app. Participants with lower income or limited health literacy had >= 50% lower odds of owning a smartphone. Comparatively, in the later sample (N = 330), almost all participants (98%) owned a smartphone and 70% of those had ever used a health app; however, disparities in health app use closely mirrored disparities in smartphone ownership from 2017 to 2018. Our findings suggest device ownership is necessary but insufficient for assuming people will use apps to support their health.